Straede Andrea, Corran Andy, Bundy James, Heinisch Jürgen J
Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastrasse 11, D-49076 Osnabrück, Germany.
Yeast. 2007 Apr;24(4):321-34. doi: 10.1002/yea.1478.
Cell integrity in Saccharomyces cerevisiae is ensured by a rigid cell wall whose synthesis is controlled by a highly conserved MAP kinase signal transduction cascade. Stress at the cell surface is detected by a set of sensors and ultimately transmitted through this cascade to the transcription factor Rlm1, which governs expression of many genes encoding enzymes of cell wall biosynthesis. We here report on a number of versatile reporter constructs which link activation of a hybrid, Rlm1-lexA, by the MAP kinase Mpk1/Slt2 to the expression of the bacterial lacZ gene. This system was adapted to automated microwell screening and shown to be activated by a number of compounds inhibiting cell wall biosynthesis or interfering with plasma membrane function. In addition, we tested tea tree oil and two of its purified constituents (alpha-terpineol, terpinen-4-ol) for their effects on growth and on cell integrity signalling using such reporter strains. Tea tree oil was found to inhibit growth of wild-type and slg1/wsc1 mutant cells at a threshold of approximately 0.1% v/v, with the purified compounds acting already at half these concentrations. A mid2 deletion displayed hyper-resistance. Tea tree oil also induces the signalling pathway in a dose-dependent manner.
酿酒酵母中的细胞完整性由一层坚硬的细胞壁来保证，其合成受一个高度保守的丝裂原活化蛋白激酶（MAP激酶）信号转导级联反应的控制。细胞表面的应激由一组传感器检测到，并最终通过这个级联反应传递给转录因子Rlm1，Rlm1调控许多编码细胞壁生物合成酶的基因的表达。我们在此报告了一些多功能报告构建体，这些构建体将MAP激酶Mpk1/Slt2对杂交体Rlm1-lexA的激活与细菌lacZ基因的表达联系起来。该系统适用于自动微孔筛选，并显示可被多种抑制细胞壁生物合成或干扰质膜功能的化合物激活。此外，我们使用此类报告菌株测试了茶树油及其两种纯化成分（α-松油醇、萜品-4-醇）对生长和细胞完整性信号传导的影响。发现茶树油在约0.1% v/v的阈值下抑制野生型和slg1/wsc1突变体细胞的生长，纯化后的化合物在这些浓度的一半时就已起作用。mid2缺失表现出超抗性。茶树油还以剂量依赖的方式诱导信号通路。
